The invention relates to a switchable component for a valve train of An internal combustion engine, with a hollow-cylindrical housing, in whose borehole an inner element that moves in the axial direction relative to the housing runs with its outer shell, wherein at least one coupling part is allocated to the inner element, wherein this coupling part lies, in the decoupled case [zero or small lift], with its outer end directly in front of an annular surface between both components and engages, in the coupled case [full lift], overlapping the annular surface in some sections, with a driver surface in the borehole of the housing, and wherein, between the components there is a lost-motion spring element, which forces these components away from each other in the axial direction.
Such switchable components, for example, switchable roller tappets, which receive force on one end from a camshaft at the bottom and which act on the other end via their inner part against a push rod, are sufficiently well known to those skilled in the art and do not need to be explained in more detail at this point. Typically, their inner part has at least one coupling piston, which, for the coupling case, can be displaced outward in the radial direction into a corresponding borehole/receptacle.
In the known state of the art, one disadvantage is that this requires excess installation space in the axial direction due to the height of the piston. In addition, in the coupled case, there is only a relatively small contact surface, so that here the hertzian stress is unnecessarily increased and it can possibly lead to undesired plastic deformation during operation. In addition, machine processing of the piston-in-borehole coupling mechanism has proven to be relatively complicated and expensive.